Transformer Paper Turns Itself Into A Robot. Cool!

This little guy changes from flat sheet of paper to critter in about four minutes.

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Originally published on August 28, 2014 6:43 pm

Every so often, a scientific paper just begs for a sexy headline.

Consider this study in the current issue of Science: "A Method for Building Self-folding Machines." A bit bland, you'll no doubt agree. A Real-Life, Origami-Inspired Transformer is how the journal's public affairs department referred to it. Now that's more like it.

Felton never intended to go into competition with Hollywood. He and his colleagues were aiming to "make robots, and machines in general, as quickly and cheaply as possible," he says. "One way to do that is to start with a flat sheet — because it's very fast and relatively cheap to make flat things."

It's now possible to print electronic circuits on a flat sheet of paper. So if you use some clever folding techniques (based on the ancient art of paper folding called origami), you can fold these sheets into useful structures — maybe a crab-shaped robot that could scuttle across the floor, or a swan-shaped robot that could really fly.

The problem is, it takes a long time for humans to make all the necessary folds in these flat sheets.

"Our goal then," Felton says, "was to try to make them fold themselves in order to save time." So he and his colleagues attached a tiny microprocessor to the paper that tells each hinge when to fold into place.

To actually accomplish the fold, the engineers use a child's toy called Shrinky Dinks. These are sheets made from elastic, shape memory polymers that shrink by about half when you heat them up. You attach the Shrinky Dink to the paper, and when the microprocessor wants to execute a particular fold, it turns on a tiny electronic heater that's printed on the paper, causing the Shrinky Dink to shrink.

"And this, in turn, pulls on the paper," Felton says, "causing the paper to fold."

He's now working on tiny, bug-size folding robots made not with paper and Shrinky Dinks but with aluminum foil and shrink-wrap. He also sees a day when there may be printable spacecraft, sent into space as flat sheets, only to fold up into something useful when they reach their target.

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AUDIE CORNISH, HOST:

It's time to unravel some news in our summer series, unfolding science. NPR science correspondent Joe Palca has been bringing us stories about the science of how things fold and unfold. He saw a report today in the journal "Science." It's about engineers who got a flat sheet of paper to fold itself into a robot, so Joe's going to tell us about how this all - well, unfolded.

JOE PALCA, BYLINE: The engineers started with a straightforward goal.

SAM FELTON: We wanted to try and make robots and machines in general as quickly and cheaply as possible.

PALCA: That's Sam Felton. He's a graduate student at the Harvard School of Engineering and Applied Sciences.

FELTON: One way to do that is to start with a flat sheet because it's very fast and it's relatively cheap to make flat things.

PALCA: And now you can print and electronic circuits on a flat sheet of paper, for example. And if you use some clever folding techniques - techniques based on the ancient art of paper folding called origami, you can fold these sheets into useful structures - maybe a crab-shaped robot that can scuttle across the floor or a bird-shaped robot that could really fly. Problem is, it takes a long time for humans to make all the complicated folds in these flat sheets.

FELTON: Our goal then, was to try and make them fold themselves in order to save time.

PALCA: So Felton and his colleagues printed hinges onto their flat sheets of paper and then attached a tiny microprocessor to the sheet.

FELTON: And it tells each hinge when to fold into place.

PALCA: Sounds simple, but I told Felton I thought I saw a problem with his scheme.

Most of the pieces of paper that I've used, even if they have electronic circuits on it, will not fold if you just tell it to.

FELTON: Of course, so our self-folding technology uses something called shape memory polymers which you might be familiar with as Shrinky Dinks.

(SOUNDBITE OF ARCHIVED RECORDING)

UNIDENTIFIED WOMAN: Welcome to the magical land of Shrinky Dinks.

PALCA: Shrinky Dinks?

FELTON: Yes.

PALCA: What? I'm sorry. Maybe I missed those in my youth, but what's a Shrinky Dink?

FELTON: It's alright. I never played with them either. It's a sheet of plastic, and the idea is that kids can draw on them and put them in the oven, and they'll shrink by 50 percent in either direction. In our case, we attached this to paper...

PALCA: And when the microprocessor wants to execute a particular fold, it turns on a tiny electronic heater printed on the paper, causing the Shrinky Dink to shrink.

FELTON: And this, in turn, pulls on the paper, causing the paper fold.

PALCA: You can watch Felton's folding robot do its folding thing at our website, npr.org. Felton is now working on tiny, bug-sized folding robots that could - I don't know - crawl into tight spaces and check for damage. Felton says you could also make larger things that fold autonomously, and I'd like to encourage him to think in that direction. How about clothes that fold themselves when they come out of the laundry? Now, that would be really welcome. Joe Palca, NPR News. Transcript provided by NPR, Copyright NPR.